Dust filter having spaced filter elements and frame for holding same



Sept. 13, 1960 G. scHNlTTKER 2,952,342 DUsT FILTER HAVING sFACED FILTER ELEMENTS AND FRAME FOR HOLDING SAME Filed Feb. 12, 1958 2 Sheets-Sheet 1 Sept. 13, 1960 G. scHNlTTKER 2,952,342

, DUST FILTER HAVING SPACED FILTER ELEMENTS AND FRAME FOR HOLDING SAME 2 Sheets-Sheet 2 Filed Feb. l2, 1958 INVENTOR.

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United States Patent() DUST FILTER HAVING SPACED FILTER ELE- MENTS AND FRAME FOR HOLDING SAME George Schnttker, 900 E. Roosevelt Road, Lombard, lll.

Filed Feb. 12, 1958, Ser. No. 714,883

1 Claim. (Cl. 189-36) particles of both large and small sizes without offering Y large resistance to flow of the air stream.

According to the present invention, the filter comprises a filter element having passages of a larger dimension than a second element having passages of a smaller dimension, the two being maintained a distance apart in a frame, the filter element having the larger dimension passages being exposed to dust laden air, and the other being exposed only to the air having some of the dust removed therefrom. The filter elements are maintained in a frame and are held a desired distance apart, and the intervening space can trap any dust dislodged from the two proximate faces of the spaced filter elements.

In a preferred embodiment of the invention the frame holding the filter elements is stitfened by providing miter elements extending inward at the frame corners and integral with the aming material. These miter elements extend inward from a web connecting a pair of spaced channels and are integral with the material forming the web. The two spaced channels afford a means of securing the filter elements in place, each such filter element being secured in a suitable frame, the sides of which bear against the side flanges of the spaced channels. The frame holding the filter elements is locked together by cooperating tangs, one of which passes through the web member and bent thereover, the other being bent over the web member from which'the tang extends.

In another embodiment of the invention the frame holding filter elements consists of a pair of spaced channels with the proximate flanges of the two channels connected by a web. In forming the frame, the remote flanges of the channels are each provided with an inturned bead and the filter elements are placed in position against the proximate flanges of the channel members, the remote flanges and the inturned beads being pressed against the filter elements to secure them in place against the inner flanges.

With the foregoing considerations in mind it is a principal object of the invention to provide an improved dust filter characterized by a pair of spaced filter elements, one having larger passages therein and being exposed to dust laden air, the other filter element being spaced from the first filter element and having smaller passage therein, and being exposed only to the air which has been partly separated from its dust content.

Another object is to provide an improved dust filter and support frame therefor, the frame being characterized by being made from a strip of sheet material and having mitered inward extending portions lending to the stiffness of the frame when assembled.

Yet another object is to provide a frame for supporting spaced filter elements, said frame being characterized by a frame with a pair of spaced channels for supporting ice spaced lter elements, the two filter elements being'placed in position by forcing the remote flanges and inturned beads thereon against the inner and proximate flanges of the two channels.

Still another object is to provide a filter frame havin an improved locking connection therefor.

Other objects and important features of the invention will be apparent from a study of the specification following taken with the drawings which together describe and illustrate some preferred embodiment of the invention and what are now considered to be the best modes of practicing the principles thereof. Other embodiments may be suggested to those having the benefit of the teachings herein, and such other embodiments are intended to be reserved especially as they fall within the scope and spirit of the subjoined claims.

In the drawings:

Fig. l is a perspective view of an improved dust filter according to one embodiment of the invention;

Fig. 2 is a plan view of a punched blank which is rolled and formed to make the frame of the dust filter seen in Fig. l; l

Fig. 3 is an end elevational view to an enlarged scale of a portion of the filter seen in Fig. 1; l

Fig. 4 is a sectional view taken along the lines 4--4` of Fig. 3 looking in the direction of the arrows;

Fig. 5 is a vertical sectional view taken along the line 5 5 of Fig. 1 looking in the direction of the arrows;

Fig. 6 is a sectional View taken along the lines 6 6 of Fig. 5 looking in the direction of the arrows; and V Fig. 7 is a sectional Iview similar to Fig. 5, showing de tails of construction according to another embodiment of the invention.

Referring now to Figs. 1 to 6 of the drawings, an improved dust filter according to one embodiment of the invention is referred to generally by the reference numeral 10 and includes a frame 11 having spaced side frame elements 12 and 13, a top frame element 14 and a bottom frame element 16. .l

As seen in Figs. 3 and 5 each of the frame elements 12, 13, 14 and 16 comprises a structural section consisting of a pair of spaced channels 17 and 18, spaced channel 17 having a remote flange 19 and an inner flange 21. Channel 18 likewise has a remote flange 22 and an inner flange 23, the inner flanges 21 and 23 being connected byfa web 24. Y

' The channels 17 Iand 18 are arranged to support filter elements 26 and 27 respectively. Each of the filter elements 26 and 27 -is held in a frame 28 having frame rails 29 and 31, each such rail having an inturned bead 32 which is closed against the filter element 26 or 27 to hold same in place there-between.

As seen in Fig. 2, the frame thus far described is lfrom a punched blank of strip material, and is punched with notches 33 forming miters 34, see Fig. 1 at the corners of the frame seen in Fig. l. The blank is also punched with dove shaped portions 36, so that when the strip seen in Fig. 2 is formed in shaping rolls and bent to the configuration seen in F-ig. l, edges 37 move into contact, with Ia portion 38 therebetween folded as seen -in Figs. 5 `and 6 to provide mitered portions 38 extending diagonally inward as seen in Figs. 5 and 6.

The aforesaid miter portions give stiffness to the frame seen in Fig. 1, to prevent warping from the plane thereof.

The side frame element 12 and the upper portion 14 `are locked together by means of a tang 39 extending from the web 24 of the top frame element 14 which enters a locking slot 41 in the web portion 24 of the side frame element 12, see Fig. 4, the tang 39 being folded over against the web 24 of the side frame element 12. The web 24 of the side frame element 12 likewise has a tang 42 whil1vcan be folded over against the web 24 of top frame element 14.

The two filter elements 26 and 27 have passageways therethrough of diflieurent'dimensions for. a purpose as nowew-i-ll be described. Asseen in Fig.` 5, filter element- 27..i s .positgioned against thez direction of flow of dust laden air and has passageways therein of relatively larger dimension to-separatefrom the dust laden air vparticles of larger size. Filter elementp26k has its passageways; of smiallendimension toy separate from theairwhichhasgbeen separated; from itslarger dust particles, the dust particles of-,smallerfdimensiom The-chamber 43 `'between the two filter elements 26 and 2,7 affordarmeans of trapping any dust dislodged from the -proxiniate-` facesof' the two filter elements, 26, and 27. nyvibrationin thesystem whereinthe filterunit 10 is employed will tend to cause thedust to be dislodgedk from thefiltergelement 26 to maintain the filter elementin good working efllciency. The filter elements 26 and 27 are made from certain types of foraminousplastic-sheet yInaterial such as polyethylene or therlike.

Referring nowto Fig. 7 of the drawings, there is shown,l another embodiment of the invention indicated generally bythe reference numeral- 50. In this case `the two lter elements 26 and 27 are not held in their individualframes, but are heldin spaced channels v51 and 52 maintained insppaced relationship by a connecting web 5?.v VEach of the channels 51 and 52, has flange portions S4 continuous with the spacing web 53, and remote flangesSG., each such flange having an inturned bead 57.

The-frame supporting the filter elements. 26 and 27 vseen. in,y the embodiment of Fig. 7 is formed from a strip similar to that seen in Fig. 2. However, in initially formf ing and rolling the strip making up the frame ofthe embodiment seenin Fig, 7, the flanges 56 are first rolled to the dotted line in position seen. The filter elements26 and v2.7 are placed' in position against the flanges 54, and the exterior flanges 56 are forced against the filter elements 26 and27' so that` each filter element is engaged between the flange 54 and the bead.57. Such operation isformedfby moving-the framebetween a pair ofrollers which presses the exterior flanges against the interior flange 5 4'in the manner las described.

j In this embodiment of the invention the filter element 27 is .the one first exposed to the dust laden air, it having the passageways oflarger dimension. The filter element ,26,1135 the passagewaysbf smaller dimension, to complete the separation of the dust from the air. The chamber; 5,8 l formed between the filter elements 26 and 27 affords a means of trapping dust dislodged from the filter elements 26' and' Z7'.

In either embodiment ofthe invention the dust can be effectively separated from the air without greatly irnpeding the movement thereof.

While the linvention has been described in terms of a number of preferred embodiments thereof, its scope is intended to be limited only by the claim herein appended.

I claim1as my invention:

A- frame Uparticularly adapted to -holdfdust filters orthe like, said frame4 comprising connected sections. each of which has a pair of spaced channels, each of said spaced channels comprisingdnner1 and outer flanges with the proximate 4inside flangesofsaid channels connected by a web, said connectedsections being formed from a flat strip which is bent along lines extending longitudinally thereof to define the aforesaid spaced channels and connecting web, cut out portions provided in said flat strip andspaced,v at intervals therealong, there being four cut out portions arranged transversely of' said strip at each interval, a pair of said cut out portions beinglocatedin those portions ofsaidflatstrip defining said outer flanges of' each section, and a further pair of said cut out -por tionsbeing in those portions of said flat strip defining the proximate inside flanges of each section. all of said cutout portions enabling said flat strip when formed in the connected sections described to be bent transversely of itself at said cutout portions so that adjacent connected sections have an included angle of saidV cutout portions providing a mitrev between the adjacent Vsections and enabling the portionA of the web between said proximate inside flanges to be bent inwardly of said frame upon itself to provide a pair ofweb portions incontact with each other capable ofV providing resistance of said connected sections to, distortion out ofthe plane of the so connected sections.

References Cited. in the fileY ofv this patent UNITED STATES PATENTS 2,818,937" Brixius Ian. 7; 195,8 

